Various types of space heaters, particularly designed for placement in inhabited spaces, such as living rooms or the like, provide combustion chambers, and include heat exchangers located in heat transfer relationship to the combustion gases emanating from the combustion chamber to heat air within the heat exchanger, which then is used to heat the surrounding space. The combustion chamber can be closed off by a transparent panel or window to give the illusion of an open fireplace. The referenced disclosure, European Published Application 0 480 870 A1, by the inventor hereof, shows one construction of this type.